From FamilySearch Wiki

After you recall and gather family information, review each document, record, letter, your interview notes, and other sources. Copy the information from these sources onto your family group record. Add custom events to the family group record for events such as religious confirmations, school, military service, land purchases, fraternal organizations, and wills written. Cite each source that documents an event listed on your family group record.

List these source documents on research logs. For suggestions on using a research log see Prepare a Research Log.